Data gaps exist in the assessment of human and environmental health largely due to the lack of ability to analyze large sample loads rapidly and cost effectively. Immunoassays (ELISA) can be used to measure toxic materials in the environment and for human monitoring because they are rapid, cost-effective, sensitive, specific and adaptable to laboratory or field situations. These assays can be used to measure potential exposure to these compounds in environmental samples such as soil and water, and in food. In the first 5 years of the Center, studies were conducted in Uruguay and elsewhere in South America that were previously cost prohibitive, thus providing an improved database from which to make informed decisions on human and environmental health. This project provides simple and reliable methods for residue analysis and a trained University staff to educate students and technicians in how to use these methods in the field. The Faculty of Chemistry, University of the Republic (Uruguay), has successfully acquired this methodology and is actively contributing to its further development. The University of California at Davis has special expertise in this area and represents an ideal training and technology transfer milieu to sponsor such a project. The project builds regional capability for using ELISA to monitor environmental contamination and to detect chemical residues in food products and drinking water, according to the needs of the region. Other trainees are learning ELISA methods to study the prevalence of hydatid cyst disease (echinococcus) in various South American countries, and to study the effectiveness of newer control strategies in Peru. We also provide laboratory training in modern molecular techniques, including RT-PCR, to analyze drinking water quality, and are developing and implementing improved curricula for graduate training of professionals in toxicology, environmental toxicology, and public health. Participants include environmental engineers, toxicologists, public health professionals, and epidemiologists, all of whom will benefit from regional-scale cooperation and improved training opportunities. [unreadable]